IBM SY44-5902-05 manual Alternate installation IPL, IPL sequence, Service processor initialization

Table 43. Methods to perform IPL (continued)

Methods	Description
F03	Attention: No system shutdown is performed before the IPL. The use of this function can
	cause loss of data.
	Control panel Function 03 starts a Load IPL. This differs from a POR IPL because no power
	off and power on sequence is done. This means a system shutdown is not performed and
	not all hardware diagnostics are performed during the IPL. Input-output processors (IOP)
	are reset using a software POR equivalent.
Programmed IPL	This IPL is started by the operating system. A PWRDWNSYS command with RESTART
without parameters	(*YES) will initiate this IPL.
Remote power on	An unattended IPL is started from a remote location (using a modem). Normal mode must
	be selected, the system power must be turned off, and the user must set specific indicators
	(see the system operation information).
Automatic restart	An unattended IPL is started automatically after a power failure. Normal mode must be
	selected and the user must set specific indicators (see the system operation information).
Power on by	This IPL is started by an internal clock. Normal mode must be selected and the user must
date/time	set specific indicators (see the system operation information).

Alternate installation IPL

To enable an alternate installation IPL, select the dedicated service tool (DST) option to Work with alternate installation device; see “Work with Dedicated Service Tools environment” on page 23 or “Work with alternate installation device” on page 27. This option is available in DST from control panel function 21 or a type D IPL. For more information about defining and enabling the alternate installation device, see Software Installation, SC41-5120-06.

IPL sequence

The IPL consists of the following steps:

1.Service processor’s performing power-on tests and loading the system processor

2.Licensed Internal Code (system) initialization

3.Installing or starting the operating system program

For information on IPL status SRCs, see “IPL status SRCs” on page 201.

Service processor initialization

Functions performed

The following list is a high-level description of the functions the service processor performs during an IPL:

1.The service processor starts by running the hardware diagnostic routines to verify the service processor’s own hardware.

2.The service processor obtains the necessary code (software) from the load source (disk or tape) to load itself and control the remainder of the IPL.

3.The service processor runs hardware diagnostic routines on the system processor.

4.The service processor loads the run-time Licensed Internal Code (system).

What is initialized

The following data areas are initialized by the service processor during an IPL:

vBus 1 I/O configuration table

218Service Functions V5R2